Multi-energy Complementarity And Optimal Scheduling Strategy For Offshore Hybrid Renewable Energy Systems

Ocean energy is diverse and abundant,and is an important clean energy source for sustainable development,with broad prospects for development.However,the problems of randomness,volatility and low energy density that exist in ocean energy prevent its largescale development and utilization.Therefore,strengthening the interconnection of multiple offshore renewable energy sources,centralizing the operation of multiple energy sources in a single system and promoting the optimization and complementarity of multiple energy sources is an effective way to achieve comprehensive utilization and coordinated dispatching among different energy sources,which can reduce the development cost of ocean energy and improve the economy and energy efficiency.In this paper,the complementarity of different energy sources is used to study the multi-energy complementary and optimal scheduling of offshore hybrid renewable energy systems.The main research work is as follows:Firstly,the stochastic characteristics and power generation characteristics of offshore wind energy,ocean thermal energy conversion and tidal energy are analyzed,and a hybrid ocean energy system model with a variety of offshore renewable energy complementary is established.The model utilizes the complementary characteristics of solar energy and ocean thermal energy conversion.Modeling analysis and simulation experiments are conducted on the complementary power generation characteristics of the two.The results show that the ocean thermal energy conversion considering the complementary characteristics has significantly improved its net power output and net thermal efficiency,and improved the overall performance from a thermodynamic point of view.At the same time,the energy storage characteristics of the dual reservoir tidal energy are deeply analyzed,and the tidal energy storage model of the dual reservoir is established and the detailed simulation analysis is carried out,which confirmed that it can achieve stable power supply to renewable energy,improve the economy of tidal power station and enhance the regulation flexibility of hybrid energy system.Secondly,a stochastic optimal scheduling model for a virtual power plant that takes into account the output intermittency of various ocean energy and the uncertainty of electricity prices in the power market is proposed.The model takes the ocean thermal energy conversion and the dual-reservoir tidal energy system as the optimal operation targets.On the premise of satisfying the constraints of the scheduling unit output,stable operation of the energy storage and safe operation of the system,the maximum expected profit of the virtual power plant is used as the optimal scheduling target.The simulation results show that the proposed model can effectively solve the uncertainty problem and improve the economic benefits of virtual power plants participating in market transactions.Finally,a multi-energy hub model of the hybrid ocean energy system is established by utilizing the coupling and complementary relationship among various offshore renewable energy sources.On this basis,considering the constraints of the operation status of various offshore energy sources,energy conversion units,energy storage equipment and other constraints,a hybrid ocean energy multi-energy scheduling strategy with the goal of maximizing the profit of the electric heating market while meeting the demand of cooling,heating and electricity is proposed.By coordinating the scheduling of each production unit and energy storage equipment,to achieve the balance of energy supply and demand and maximize profit during the operation of the energy hub.The results of comparison examples of different typical scenarios show that the model can effectively improve the overall efficiency of the system and provide a new method for the economic operation of the energy hub and the consumption of ocean energy.In summary,this paper focuses on the characteristics of a variety of offshore renewable energy,considers the complementary characteristics of solar-ocean thermal energy conversion and tidal energy storage characteristics,and establishes a hybrid ocean energy system,and proposes an optimal scheduling of hybrid ocean energy virtual power plants.The model provides solutions to improve the optimality and scalability of ocean energy dispatch by establishing multiple energy hubs with complementary ocean energy.